Effect Evaluation on the Comprehensive Management for Shiyang River Basin from the Perspective of Temporal and Spatial Changes of Vegetation Coverage in Minqin Basin

PurposeThrough a comparative of ecological environment changes in Minqin Basin before and after a national ecological restoration engineering, named the comprehensive management of the Shiyang River Basin, this study aimed to provide a theoretical basis for the implementation of the project and the ecological restoration policy of the inland river basins in the northwest.

MethodTaking the Minqin Basin, the typical desert-oasis ecosystem in the downstream of Shiyang River as the study area, and using Landsat images as the data source, we studied the spatial and temporal changes of vegetation coverage in 2000 (before ecological restoration), 2006 (start ecological restoration), 2010 (ecological restorationⅠperiod) and 2016 (ecological restorationⅡ period) as the remote sensing retrieval methods of fractional vegetation coverage based on NDVI pixel dichotomy model.

Result(1) From 2000 to 2016, the areas of low and high vegetation coverage in the entire study area increased by 7.71% and 0.71%, respectively. The average vegetation coverage increased by 0.13% per year, and the area of slight and moderate improvement reached 6.39% and 0.56%, respectively. The improvement effects were obvious especially in the ecological restoration Ⅱ period (2010—2016) was the most obvious. (2) After the implementation of ecological restoration, the areas of low and high vegetation coverage areas in the oasis in 2016 increased by 1.05% and 2.88% respectively in 2016 compared with 2000; the area of no vegetation coverage decreased from 56.98% (2000) to 47.27% (2016), while the area of low vegetation coverage increased by 11.30% in the desert. (3) The ecological restoration of Qingtu Lake, Huangantan and Laohukou are the most typical regions for ecological restoration.

ConclusionWith the implementation of comprehensive management of Shiyang River Basin, the vegetation coverage and area of Minqin Basin have a clear development trend, and the comprehensive restoration of Shiyang River Basin has obvious ecological restoration effect.